A solo mother cried in the dock after escaping jail on her sixth drink-driving conviction - this time with a high level and three pre-school children in the car.

Instead, Amy Kathleen Reilly, 28, will serve six months of home detention at her home, and will do drug and alcohol rehabilitation.

She is also disqualified from driving indefinitely for what her defence counsel Craig Fletcher accepted was an "astronomical" breath-alcohol level, at her Christchurch District Court sentencing.

Reilly was driving on the afternoon of June 19, and crashed into a power pole on Bower Ave, New Brighton.

When she was tested, she had 1409mcg of alcohol to a litre of breath.

The legal limit is 400mcg.

There were three children in the car.

Fletcher said that when Reilly chose to drive that day "her reasoning had basically left her and her behaviour was inappropriate".

She now had the care of four children.

Child, Youth and Family had some oversight over the family, and Reilly had done a City Mission detoxification programme.

He urged that community detention be imposed to make it easier for Reilly to seek alternative accommodation when she had to leave her present red-zoned property in April.

But Judge Phillip Moran said he would normally have been looking at an 18-month prison term for her offending, after her guilty pleas to charges of repeat drink-driving, careless driving, and driving while forbidden.

Reilly was upset and crying as the sentencing continued.

The judge said she was a young solo mother who was still coming to terms with addiction problems that had bedevilled her life.

"You are not a hardened criminal," he told her.

He reduced her home detention term because of the accommodation difficulties it would pose.

He imposed a six-month term, with drug rehabilitation, and an indefinite disqualification.

She will not be allowed to apply to the Director of Land Transport to get her licence back for at least a year, and she will require a "clean bill of health" from an alcohol assessment.